Silver pigments

ABSTRACT

The present invention relates to silver pigments based on transparent, low-refractive-index, platelet-shaped substrates which have a high-refractive-index coating consisting of TiO 2  having a layer thickness of 5-300 nm and optionally an outer protective layer, and to the use thereof in paints, coatings, printing inks, security printing inks, plastics, button pastes, ceramic materials, glasses, for seed coloring, as dopants in the laser marking of plastics and papers, as additives for coloring in the foods and pharmaceuticals sectors, and in cosmetic formulations and for the preparation of pigment compositions and dry preparations.

[0001] The present invention relates to silver interference pigmentsbased on platelet-shaped, transparent, low-refractive-index substratesand to the use thereof in paints, coatings, printing inks, plastics, asdopants for the laser marking of plastics and papers, as additives inthe foods and pharmaceuticals sectors and in cosmetic formulations.

[0002] Luster or effect pigments are employed in many areas of industry,in particular in the area of automotive finishes, decorative coatings,plastics, paints, printing inks and in cosmetic formulations.

[0003] Owing to their color play, Luster pigments, which exhibit anangle-dependent color change between a plurality of interference colors,are of particular interest for automotive finishes and in forgery-proofdocuments of value.

[0004] Mineral-based pearlescent pigments are of particular importance.Pearlescent pigments are prepared by coating an inorganic,platelet-shaped support with a high-refractive-index, usually oxidiclayer. The color of these pigments is caused by wavelength-selectivepartial reflection and interference of the reflected or transmittedlight at the medium/oxide or oxide/substrate interfaces.

[0005] The interference color of these pigments is determined by thethickness of the oxide layer. The hue of a silver pigment is generatedby a (in the optical sense) single high-refractive-index layer whoseoptical thickness causes a reflection maximum (1st order) in the visiblewavelength range at about 500 nm. This wavelength is perceived by thehuman eye as the color green. However, the intensity curve of thismaximum on its wavelength axis is so broad that so much light isreflected throughout the region of visible light that the human eyeperceives a very bright, but colorless impression.

[0006] According to the known rules—in particular from the coating ofoptical components—of the optics of thin layers, the intensity of thereflected light in an arrangement of a plurality of layers withalternating high and low refractive indexes increases greatly comparedwith a single layer. Thus, the application of a TiO₂—SiO₂—TiO₂ layersystem to mica particles increases the intensity of the reflected lightby about 60% compared with a TiO₂ single-layer system. Accordingly, theprofile of the light reflected by interference is significantly morepronounced, so that an intense and bright reflection color must beexpected for a multilayered system of this type. Pigments of this typeare described in DE 196 18 569 A1.

[0007] The prior art discloses silver pigments based on mica plateletswhich have a very broad scattering of the layer thickness and thereforehave a neutral behavior with respect to the interference color.Pearlescent pigments that have a single high-refractive-index coating ofmica therefore represent single-layer optical systems, i.e. theinterference color is determined exclusively by the layer thickness ofthe high-refractive-index metal-oxide layer. The coloristic designlatitude of a mica/metal oxide silver pigment is therefore veryrestricted.

[0008] In addition, mica particles, owing to their layer structure, haveirregularities on the surface which cause scattering and thus reduce thetransparency and coloristic quality of the product. Furthermore, micaexhibits a more or less highly pronounced grey-brown body color. Thisproperty reduces the transparency further and influences the absorptioncolor of the application media in an undesired manner.

[0009] Furthermore, multilayered pigments which cause a silver colorimpression, as described, for example, in EP 1213330 A1, are known. Inthe case of these pigments, an intense color can be suppressed by theSiO₂ layer of the TiO₂—SiO₂—TiO₂ layer sequence having been applied verythinly (about 50 nm). These pigments, like the single-layered mica-basedsilver pigments, offer only a very small latitude in the design of thecoloristic properties and have the above-mentioned disadvantages of micaas substrate.

[0010] The object of the present invention is therefore to provide asilver-colored interference pigment which is distinguished, inparticular, by high transparency, a pure-white body color and coloristicdesign possibilities which go beyond an exclusively silver effect.

[0011] Surprisingly, it has now been found that a specific transparent,low-refractive-index platelet, such as, for example, an SiO₂ platelet,coated with a thin TiO₂ layer causes a silver color impression. This isachieved through the coating of the platelet with a TiO₂ layer whosethickness is “matched” precisely to the thickness of the platelet.

[0012] The interference color of a thin layer is determined by itsthickness. In a lamellar thin layer system like coated thin plateletsthe color is a result of the reflection of the whole stack of layers asone reflection system.

[0013] On substrates with somewhat different mean thickness similarcolor effects can be achieved by “matching” of the thickness of thetitanium dioxide coating. This is done by color measurements during thecoating process and interruption of the coating process when the desiredcolor on the respective substrate is obtained.

[0014] To maintain the described silver color effect on substrates withdifferent mean thickness it is necessary to choose an individual coatingthickness for every particular substrate thickness. This is also done bythe above described matching of coating thickness.

[0015] Compared with single-coated mica-based silver pigments and theinterference pigments from EP 1213330 A1, the pigments according to theinvention exhibit the following properties:

[0016] excellent transparency in the application medium

[0017] pure-white body color

[0018] very bright silver interference color.

[0019] In addition to these properties, the pigments according to theinvention are distinguished over the known interference pigments by thefollowing features:

[0020] strong sparkle effect

[0021] adjustable hue

[0022] angle-dependence of the hue

[0023] The said hue can be varied over a broad range by adjusting (i.e.,“matching”) the TiO₂ layer thickness and through the choice oftransparent platelets, such as, for example, SiO₂ platelets, of variousthickness without losing the impression of an interference pigment. Suchmatching as described above, is conventional.

[0024] The invention therefore relates to silver interference pigmentsbased on platelet-shaped, transparent, low-refractive-index substrateswhich have a high-refractive-index coating consisting of TiO₂ having alayer thickness of 5-300 nm and optionally an outer protective layer.

[0025] The invention furthermore relates to the use of the silverpigments according to the invention in paints, coatings, printing inks,plastics, button pastes, ceramic materials, glasses, for seed coating,as dopants in the laser marking of plastics and papers, as additives forcoloring in the foods and pharmaceuticals sectors and in particular incosmetic formulations. The pigments according to the invention arefurthermore also suitable for the preparation of pigment compositionsand for the preparation of dry preparations, such as, for example,granules, chips, pellets, briquettes, etc. The dry preparations areparticularly suitable for printing inks and for cosmetic formulations.

[0026] Suitable substrates are all low refractive index inorganic andorganic transparent materials which can be produced in the form offinely divided platelets having a narrow thickness distribution.Suitable organic substrates are, inter alia, polymers, such as, forexample, polyesters (for example PET), polycarbonates, polyimides andpolymethacrylates.

[0027] Suitable base substrates for the interference pigments accordingto the invention are substrates having a refractive index of <1.9, forexample platelet-shaped SiO₂ platelets, as described, for example, in WO93/08237. Furthermore, besides the said SiO₂ platelets, anyplatelet-shaped, transparent substrate known to the person skilled inthe art, such as, for example, Al₂O₃ platelets, glass platelets andplatelet-shaped plastic particles, is suitable. Very particularlypreferred substrates are SiO₂ platelets. The particular properties, suchas the tuneable hue and in particular the angle dependence thereof, areparticularly supported by a defined average density with a narrowthickness distribution.

[0028] Particular preference is given to the production of interferencepigments based on substrates of SiO₂, Al₂O₃, all single crystals with aflaky appearance and glass platelets, all coated with a thin titaniumdioxide layer.

[0029] The standard deviation of the thickness of the substrateplatelets is therefore ≦20%, more preferably ≦10% and particularlypreferably ≦5%, based on the average layer thickness thereof.

[0030] “Low” refractive index is understood in the art to refer tomaterials with refractive index ≦1.9, while “high” refractive indexrefers to >1.9.

[0031] The size of the base substrate is not crucial per se and can bematched to the particular application. In general, the platelet-shapedtransparent substrates have an average thickness of between 0.02 and 10μm, preferably between 0.03 and 5 μm, in particular between 0.05 and 3μm. The size in the two other dimensions is usually between 1 and 450μm, preferably between 2 and 200 μm and in particular between 5 and 100μm.

[0032] The aspect ratio (diameter/thickness ratio) of the substrate ispreferably 1-1000, in particular 3-500 and very particularly preferably5-200.

[0033] The thickness of the TiO₂ layer and of the substrate, for exampleSiO₂ substrate, is important for the optical properties of the pigment.The thickness of the layer is preferably set precisely and matched tothe average thickness of the substrate platelets. Preference is given toTiO₂ layer thicknesses of 5-300 nm, preferably 10-200 nm, in particular30-150 nm.

[0034] The pigments according to the invention can be preparedrelatively easily by forming a high-refractive-index TiO₂ interferencelayer having precisely defined thickness and a smooth surface on thefinely divided, platelet-shaped substrates. The TiO₂ can be either inthe form of rutile or in the form of anatase. The TiO₂ is preferably inthe rutile modification. Particular preference is given to SiO₂platelets coated with a rutile layer.

[0035] The metal-oxide layer is preferably applied by wet-chemicalmethods, it being possible to use the wet-chemical coating methodsdeveloped for the preparation of pearlescent pigments. Methods of thistype are described, for example, in DE 14 67 468, DE 19 59 988, DE 20 09566, DE 22 14 545, DE 22 15 191, DE 22 44 298, DE 23 13 331, DE 25 22572, DE 31 37 808, DE 31 37 809, DE 31 51 343, DE 31 51 354, DE 31 51355, DE 32 11 602, DE 32 35 017, and also in further patent documentsand other publications known to the person skilled in the art.

[0036] In the case of wet coating, the substrate particles are suspendedin water, and one or more hydrolysable titanium salts are added at a pHwhich is suitable for hydrolysis, the latter being selected in such away that the metal oxides or metal oxide hydrates are precipitateddirectly onto the platelets without significant secondary precipitationsoccurring. The pH is usually kept constant by simultaneous metering-inof a base and/or acid. The pigments are subsequently separated off,washed and dried at 50-150° C. and, if desired, calcined for 0.5-3hours, where the calcination temperature can be optimised with respectto the coating present in each case. In general, the calcinationtemperatures are between 250 and 1000° C., preferably between 350 and950° C.

[0037] The coating can furthermore also be carried out in afluidised-bed reactor by gas-phase coating, it being possible, forexample, correspondingly to use the processes proposed in EP 0 045 851A1 and EP 0 106 235 A1 for the preparation of pearlescent pigments.Thus, the pigments of the invention can also be prepared by hydrolyticdecomposition of metal salts in aqueous medium or by thermaldecomposition by a CVD or PVD process.

[0038] The hue of the pigments can be varied within very broad limitswhile retaining the silver effect by choosing different covering amountsor layer thicknesses resulting therefrom. The fine tuning for a certainhue can be achieved beyond the pure choice of amount by approaching thedesired color under visual or measurement technology control.

[0039] In order to increase the light, water and weather stability, itis frequently advisable, depending on the area of application, tosubject the finished pigment to post-coating or post-treatment. Suitablepost-coatings or post-treatments are the processes described, forexample, in German Patent 22 15 191, DE-A 31 51 354, DE-A 32 35 017 andDE-A 33 34 598. This post-coating further increases the chemicalstability or simplifies handling of the pigment, in particularincorporation into various media. In order to improve the wettability,dispersibility and/or compatibility with the application media,functional coatings of Al₂O₃ or ZrO₂ or mixtures or mixed phases thereofmay be applied to the pigment surface furthermore, organic or combinedorganic/inorganic post-coatings are possible, for example with silanes,as described, for example, in EP 0090259, EP 0 634 459, WO 99/57204, WO96/32446, WO 99/57204, U.S. Pat. No. 5,759,255, U.S. Pat. No. 5,571,851,WO 01/92425 or in J. J. Ponjee, Philips Technical Review, Vol. 44, No.3, 81 ff., and P. H. Harding J. C. Berg, J. Adhesion Sci. Technol.Vol.11 No. 4, pp. 471-493.

[0040] The silver pigments according to the invention are simple andeasy to handle. The pigments can be incorporated into the applicationsystem by simple stirring-in. Complex grinding and dispersal of thepigments is not necessary.

[0041] Since the silver pigments according to the invention combine highgloss with high transparency and a pure-white body color, they enableparticularly effective effects to be achieved in the various applicationmedia without the absorption color being significantly affected.

[0042] It goes without saying that, for the various applications, theinterference pigments can also advantageously be used in the form of amixture with organic dyes, organic pigments or other pigments, such as,for example, transparent and opaque white, colored and black pigments,and with platelet-shaped iron oxides, organic pigments, holographicpigments, LCPs (liquid crystal polymers) and conventional transparent,colored and black Luster pigments based on metal oxide-coated mica andSiO₂ platelets, etc. The interference pigments can be mixed in any ratiowith commercially available pigments and fillers.

[0043] In the various applications, the pigment according to theinvention can also be combined with further colorants of any type, forexample organic and/or inorganic absorption pigments and dyes,multilayered interference pigments, such as, for example, Timiron®,Sicopearl® (BASF AG), ChromaFlair® (Flex Products Inc.), BiOCl pigments,pearl essence or metal pigments, for example from Eckart. There are nolimits to the mixing ratios and concentration.

[0044] The pigments according to the invention are compatible with amultiplicity of color systems, preferably from the area of paints,coatings and printing inks. For the production of printing inks for, forexample, gravure printing, flexographic printing, offset printing oroffset overprinting, a multiplicity of binders, in particularwater-soluble grades, as marketed, for example, by BASF, Marabu, Pröll,Sericol, Hartmann, Gebr. Schmidt, Sicpa, Aarberg, Siegberg, GSB-Wahl,Follmann, Ruco or Coates Screen INKS GmbH, are suitable. The printinginks may be water-based or solvent-based. The pigments are furthermorealso suitable for the laser marking of paper and plastics and forapplications in the agricultural sector, for example for greenhousesheeting, and, for example, for the coloring of tent awnings.

[0045] The silver pigment according to the invention can be used for thepigmenting of surface coatings, printing inks, plastics, agriculturalsheeting, seed coatings, food colorings, button pastes, medicamentcoatings or cosmetic formulations, such as lipsticks, nail varnishes,compact powders, shampoos, loose powders and gels. The concentration ofthe pigment mixture in the application system to be pigmented isgenerally between 0.1 and 70% by weight, preferably between 0.1 and 50%by weight and in particular between 0.5 and 10% by weight, based on thetotal solids content of the system. It is generally dependent on thespecific application.

[0046] Plastics comprising the silver pigment according to the inventionin amounts of from 0.01 to 50% by weight, in particular from 0.1 to 7%by weight, are frequently distinguished by a particularly pronouncedsparkle effect.

[0047] In the surface coatings sector, in particular in automotivepaints, the silver pigment is also employed for three-coat systems inamounts of 0.1-10% by weight, preferably from 1 to 3% by weight.

[0048] In surface coatings, the pigment according to the invention hasthe advantage that the target gloss is achieved by a one-coat finish(one-coat system or base coat in two-coat systems). Compared withfinishes comprising a mica-based multilayered pigment instead of thesilver pigment according to the invention, finishes comprising thepigment according to the invention exhibit a clearer depth effect and amore highly pronounced gloss effect.

[0049] The silver pigment according to the invention can alsoadvantageously be employed in decorative and care cosmetics. The useconcentration extends from 0.01% by weight in shampoos to 100% by weightin the case of loose powders. In the case of a mixture of the silverpigments with spherical fillers, for example SiO₂, the concentration canbe 0.01-70% by weight in the formulation. The cosmetic products, suchas, for example, nail varnishes, lipsticks, compact powders, shampoos,loose powders and gels, are distinguished by particularly interestinggloss effects. The sparkle effect in nail varnish can be significantlyincreased compared with conventional nail varnishes with the aid of thepigments according to the invention. Furthermore, the pigment accordingto the invention can be employed in bath additives, toothpastes and forthe finishing of foods, for example mass coloring and/or coatings ofboiled sweets, wine gums, such as, for example, jelly babies, pralines,liquorice, confectionery, sticks of rock, fizzy drinks, sodas, etc., oras a coating, for example, in standard and coated tablets in thepharmaceuticals sector.

[0050] The pigment according to the invention can furthermore be mixedwith commercially available fillers. Fillers which may be mentioned are,for example, natural and synthetic mica, nylon powder, pure or filledmelamine resins, talc, glasses, kaolin, oxides or hydroxides ofaluminium, magnesium, calcium, zinc, BiOCl, barium sulfate, calciumsulfate, calcium carbonate, magnesium carbonate, carbon, and physical orchemical combinations of these substances. There are no restrictionsregarding the particle shape of the filler. It can be, for example,platelet-shaped, spherical or needle-shaped in accordance withrequirements.

[0051] It is of course also possible for the pigments according to theinvention to be combined in the formulations with cosmetic raw materialsand assistants of any type. These include, inter alia, oils, fats,waxes, film formers, preservatives and assistants which generallydetermine the technical properties, such as, for example, thickeners andTheological additives, such as, for example, bentonites, hectorites,silicon dioxides, Ca silicates, gelatins, high-molecular-weightcarbohydrates and/or surface-active assistants, etc.

[0052] The formulations comprising the pigments according to theinvention can belong to the lipophilic, hydrophilic or hydrophobic type.In the case of heterogeneous formulations having discrete aqueous andnon-aqueous phases, the pigments according to the invention may in eachcase be present in only one of the two phases or alternativelydistributed over both phases.

[0053] The pH values of the formulations can be between 1 and 14,preferably between 2 and 11 and particularly preferably between 5 and 8.

[0054] No limits are set for the concentrations of the pigmentsaccording to the invention in the formulation. They can be—depending onthe application—between 0.001 (rinse-off products, for example showergels) and 100% (for example gloss-effect articles for particularapplications).

[0055] The pigments according to the invention may furthermore also becombined with cosmetic active ingredients. Suitable active ingredientsare, for example, insect repellents, UV A/BC protective filters (forexample OMC, B3 and MBC), anti-ageing active ingredients, vitamins andderivatives thereof (for example vitamin A, C, E, etc.), self-tanningagents (for example DHA, erythrulose, inter alia), and further cosmeticactive ingredients, such as, for example, bisabolol, LPO, ectoin,emblica, allantoin, bioflavonoids and derivatives thereof.

[0056] In the pigmenting of binder systems, for example for surfacecoatings and printing inks for gravure printing, offset printing orscreen printing, or as precursors for printing inks, the use of theinterference pigments according to the invention in the form of highlypigmented pastes, granules, pellets, etc., has proven particularlysuitable. The pigment is generally incorporated into the printing ink inamounts of 2-35% by weight, preferably 5-25% by weight and in particular8-20% by weight. Offset printing inks can comprise the pigments inamounts of up to 40% by weight or more. The precursors for printinginks, for example in the form of granules, as pellets, briquettes, etc.,comprise up to 98% by weight of the pigment according to the inventionin addition to the binder and additives. Printing inks comprising thepigment according to the invention exhibit purer silver hues than withconventional effect pigments. The particle thicknesses of the pigmentsaccording to the invention are relatively small and therefore effectparticularly good printability.

[0057] The interference pigments according to the invention arefurthermore suitable for the preparation of flowable pigmentcompositions and dry preparations, in particular for printing inks,comprising one or more silver pigments according to the invention,binders and optionally one or more additives.

[0058] The invention thus also relates to formulations comprising thesilver pigment according to the invention.

[0059] Without further elaboration, it is believed that one skilled inthe art can, using the preceding description, utilize the presentinvention to its fullest extent. The following preferred specificembodiments are, therefore, to be construed as merely illustrative, andnot limitative of the remainder of the disclosure in any way whatsoever.

[0060] In the foregoing and in the following examples, all temperaturesare set forth uncorrected in degrees Celsius and, all parts andpercentages are by weight, unless otherwise indicated.

EXAMPLES Example 1 Silver Pigment with Color Travel from Green ViaRed-Violet to Gold-Green

[0061] 100 g of SiO₂ platelets (particle size 5-50 μm, average thickness450 nm, standard deviation of the thickness: 5%) are suspended in 2 l ofdeinonized water and heated to 80° C. with vigorous stirring. A solutionof 12 g of SnCl₄×5 H₂O and 40 ml of hydrochloric acid (37%) in 360 ml ofdeinonized water is metered into this mixture at pH 1.6 at a rate of 4ml/min. 370 ml of TiCl₄ solution (400 g of TiCl₄/l) are subsequentlymetered in at a pH of 1.6 at a rate of 2 ml/min. The pH is kept constantduring the addition of both the SnCl₄×5 H₂O solution and TiCl₄ solutionsusing NaOH solution (32%). The pH is subsequently adjusted to 5.0 usingsodium hydroxide solution (32%), and the mixture is stirred for afurther 15 minutes.

[0062] For work-up, the pigment is filtered off, washed with 20 l ofdeinonized water, dried at 110° C. and calcined at 850° C. for 30minutes. The product is a silver interference pigment having a slightgreen tint which shifts via red-violet to gold-green when viewed at anangle.

Example 2 Silver Pigment with Color Travel from Neutral Silver ViaRed-Violet to Gold-Yellow

[0063] 100 g of SiO₂ platelets (particle size 5-50 μm, average thickness450 nm, standard deviation of the thickness: 5%) are suspended in 2 l ofdeinonized water and heated to 80° C. with vigorous stirring. A solutionof 12 g of SnCl₄×5 H₂O and 40 ml of hydrochloric acid (37%) in 360 ml ofdeinonized water is metered into this mixture at pH 1.6 at a rate of 4ml/min. 350 ml of TiCl₄ solution (400 g of TiCl₄/l) are subsequentlymetered in at a pH of 1.6 at a rate of 2 ml/min. The pH is kept constantduring the addition of both the SnCl₄×5 H₂O solution and TiCl₄ solutionsusing NaOH solution (32%). The pH is subsequently adjusted to 5.0 usingsodium hydroxide solution (32%), and the mixture is stirred for afurther 15 minutes. For work-up, the pigment is filtered off, washedwith 20 l of deinonized water, dried at 110° C. and calcined at 850° C.for 30 minutes. The product is a silver interference pigment whose colorshifts via red-violet to gold-yellow when viewed at an angle.

Example 3 Silver Pigment with Color Travel from Slightly Bluish SilverVia Red to Gold-Green

[0064] 100 g of SiO₂ platelets (particle size 5-50 μm, average thickness450 nm, standard deviation of the thickness: 5%) are suspended in 2 l ofdeinonized water and heated to 80° C. with vigorous stirring. A solutionof 12 g of SnCl₄×5 H₂O and 40 ml of hydrochloric acid (37%) in 360 ml ofdeinonized water is metered into this mixture at pH 1.6 at a rate of 4ml/min. 340 ml of TiCl₄ solution (400 g of TiCl₄/l) are subsequentlymetered in at a pH of 1.6 at a rate of 2 ml/min. The pH is kept constantduring the addition of both the SnCl₄×5 H₂O solution and TiCl₄ solutionsusing NaOH solution (32%). The pH is subsequently adjusted to 5.0 usingsodium hydroxide solution (32%), and the mixture is stirred for afurther 15 minutes.

[0065] For work-up, the pigment is filtered off, washed with 20 l ofdeinonized water, dried at 110° C. and calcined at 850° C. for 30minutes. The product is a silver interference pigment whose color shiftsvia red to gold-green when viewed at an angle.

USE EXAMPLES Example A Shimmering Foundation

[0066] Raw material Source of supply INCI [%] Phase A Extender W MerckKGaA/Rona ® MICA, CI 77891 9.00 (Titanium Dioxide) MICRONA ® MatteYellow Merck KGaA/Rona ® MICA, CI 77492 (Iron 4.00 Oxides) MICRONA ®Matte Red Merck KGaA/Rona ® MICA, CI 77491 (Iron 0.40 Oxides) MICRONA ®Matte Black Merck KGaA/Rona ® MICA, CI 77499 (Iron 0.30 Oxides) Pigmentfrom Example 1 Merck KGaA 4.50 RONASPHERE ® Merck KGaA/Rona ® SILICA5.00 Phase B Blanose 7 HF Aqualon GmbH Cellulose Gum 0.20 VeegumVanderbilt Magnesium Aluminium 1.00 Silicate Texapon K 1296 Cognis GmbHSodium Lauryl Sulfate 0.60 Triethanolamine extra Merck KGaA/Rona ®Triethanolamine 0.50 pure Titriplex III Merck KGaA/Rona ® Disodium EDTA0.25 Methyl 4-hydroxy- Merck KGaA/Rona ® Methylparaben 0.15 benzoate1,2-Propanediol Merck KGaA/Rona ® Propylene Glycol 10.90 Water,demineralised Aqua (Water) 42.95 Phase C Isopropyl myristate Cognis GmbHIsopropyl Myristate 8.00 Liquid paraffin Merck KGaA/Rona ® ParaffinumLiquidum 3.60 (Mineral Oil) Crodamol SS Croda GmbH Cetyl Esters 2.60Monomuls 60-35 C Cognis GmbH Hydrogenated Palm 1.70 Glycerides Stearicacid Merck KGaA/Rona ® Stearic Acid 1.50 EUSOLEX ® 6300 MerckKGaA/Rona ® 4-Methylbenzylidene 1.30 Camphor EUSOLEX ® 4360 MerckKGaA/Rona ® Benzophenone-3 0.50 Rona Care ™ Merck KGaA/Rona ® TocopherylAcetate 0.50 Tocopherol acetate Magnesium stearate Merck KGaA/Rona ®Magnesium Stearate 0.10 Propyl 4-hydroxy- Merck KGaA/Rona ®Propylparaben 0.05 benzoate Phase D Perfume oil 200 529 FragrancePerfume 0.20 Resources Euxyl K 400 Schulke & Mayr Phenoxyethanol, 0.20GmbH Methyldibromo, Glutaronitrile

[0067] Preparation:

[0068] Melt and stir all constituents of phase C at about 75° C. untileverything has melted. Initially introduce the water of phase B cold,homogenize in the Blanose using the Turrax, scatter in the Veegum, andre-homogenize. Warm to 75° C. and dissolve the other constituentstherein with stirring. Stir in the constituents of phase A. Add phase Cat 75° C. with stirring and homogenize for 2 minutes. Cool the mixtureto 40° C. with stirring, add phase D. Cool further to room temperaturewith stirring and adjust to pH 6.0-6.5 (for example using citric acidsolution).

Example B Shower Gel

[0069] Raw material Source of supply INCI [%] Phase A Pigment fromExample 2 Merck KGaA 0.10 Keltrol T Kelco Xanthan Gum 0.75 Water,demineralised Aqua (Water) 64.95 Phase B Plantacare 2000 UP Cognis GmbHDecyl Glucoside 20.00 Texapon ASV 50 Cognis GmbH Sodium Laureth Sulfate,3.60 Sodium Laureth-8 Sulfate, Magnesium Laureth Sulfate, MagnesiumLaureth-8 Sulfate, Sodium Oleth Sulfate, Magnesium Oleth SulfateBronidox L Cognis GmbH Propylene Glycol, 0.20 5-Bromo-5-Nitro-1,3-Dioxane Perfume oil Everest Haarmann & Perfume 0.05 79658 SB (deleted)Reimer GmbH 1% FD&C lue No. 1 in BASF AG Aqua (Water), CI 42090 0.20water (FD&C Blue No. 1) Phase C Citric acid monohydrate MerckKGaA/Rona ® Citric Acid 0.15 Water, demineralised Aqua Water 10.00

[0070] Preparation:

[0071] For phase A, stir the pigment into the water. Slowly scatter inthe Keltril T with stirring and stir until it has dissolved. Add phasesB and C successively while stirring slowly until everything ishomogeneously distributed. Adjust the pH to from 6.0 to 6.4.

Example C Eyeliner Gel

[0072] Raw material Source of supply INCI [%] Phase A Pigment fromExample 3 Merck KGaA 5.00 Xirona ® Magic Mauve Merck KGaA/Rona ® Silica,CI 77891 10.00 (Titanium Dioxide), Tin oxide Mica Black MerckKGaA/Rona ® CI 77499 (Iron Oxides), 5.00 MICA, CI 77891 (TitaniumDioxide) RONASPHERE ® Merck KGaA/Rona ® Silica 2.00 Carbopol ETD 2001 BFGoodrich Carbomer 0.40 Citric acid monohydrate Merck KGaA/Rona ® CitricAcid 0.00 Water, demineralised Aqua (Water) 60.00 Phase B Glycerol,anhydrous Merck KGaA/Rona ® Glycerin 4.00 Triethanolamine extra MerckKGaA/Rona ® Triethanolamine 0.90 pure Luviskol VA 64 Powder BASF AGPVP/VA Copolymer 2.00 Germaben II ISP Global Propylene Glycol, 1.00Technologies Diazolidinyl Urea, Methylparaben, Propylparaben Water,demineralised Aqua (Water) 9.70

[0073] Preparation:

[0074] Disperse the effect pigments and Ronasphere® in the water ofphase A. Acidify using a few drops of citric acid in order to reduce theviscosity, scatter in the Carbopol with stirring. After completedissolution, slowly stir in the pre-dissolved phase B and adjust the pHto from 7.0 to 7.5.

Example D Eye Shadow

[0075] Raw material Source of supply INCI [%] Phase A Xirona ® CaribbeanBlue Merck KGaA/Rona ® Silica, CI 77891 45.00 (Titanium Dioxide), Mica,Tin Oxide Mica Black Merck KGaA/Rona ® CI 77499 (Iron Oxides), 5.00MICA, CI 77891 (Titanium Dioxide) Pigment from Example 1 Merck KGaA 5.00BIRON ® B 50 Merck KGaA/Rona ® CI 77163 (Bismuth Oxy-chloride) 3.00Colorona ® Dark Blue Merck KGaA/Rona ® MICA, CI 77891 10.00 (TitaniumDioxide), CI 77510 (Ferric Ferro-cyanide) Magnesium stearate MerckKGaA/Rona ® Magnesium Stearate 2.50 White clay (deleted) MerckKGaA/Rona ® Kaolin 5.00 Hubersorb 600 J.M. Huber Corp. Calcium Stearate0.50 Talc Merck KGaA/Rona ® Talc 11.00 Phase B Amerchol L 101 AmercholLanolin Alcohol, 10.70 Paraffinum Liquidum (Mineral Oil) Super HartolanCroda GmbH Lanolin Alcohol 1.00 Ewalin 1751 H. Erhard Wagner Petrolatum1.00 GmbH Propyl 4-hydroxy- Merck KGaA/Rona ® Propylparaben 0.10benzoate Perfume oil Elegance # Haarmann & Perfume 0.20 79228 D MFReimer GmbH

[0076] Preparation:

[0077] Combine and pre-mix the constituents of phase A. Subsequently addthe molten phase B dropwise to the powder mixture with stirring. Thepowders are pressed at from 40 to 50 bar.

Example E Eye Shadow Gel

[0078] Raw material Source of supply INCI [%] Phase A Xirona ® IndianMerck KGaA/Rona ® Silica, Cl 77491 (Iron 15.00 Summer Oxides) Pigmentfrom Example 3 Merck KGaA 5.00 RONASPHERE ® Merck KGaN/Rona ® SILICA3.00 Carbopol ETD 2001 BF Goodrich GmbH CARBOMER 0.30 Citric acidmonohydrate Merck KGaA/Rona ® Citric Acid 0.00 Water, demineralized Aqua(Water) 60.00 Phase B Glycerol, anhydrous Merck KGaA/Rona ® Glycerin2.00 Germaben II ISP Global Propylene Glycol, 0.20 TechnologiesDiazolidinyl Urea, Methylparaben, Propylparaben Triethanolamine extraMerck KGaA/Rona ® Triethanolamine 0.70 pure Water, demineralized Aqua(Water) 13.80

[0079] Preparation:

[0080] Disperse the effect pigments and Ronasphere® in the water ofphase A. Acidify using a few drops of citric acid in order to reduce theviscosity, scatter in the Carbopol with stirring. After completedissolution, slowly stir in the pre-dissolved phase B.

Example F Eye Shadow

[0081] Raw material Source of supply INCI [%] Phase A Xirona ® CaribbeanBlue Merck KGaA/Rona ® Silica, Cl 77891 20.00 (Titanium Dioxide), MICA,TIN Oxide Colorona ® Dark Blue Merck KGaA/Rona ® MICA, Cl 77891 5.00(Titanium Dioxide), Cl 77510 (Ferric Ferro-cyanide) Pigment from Example2 Merck KGaA 5.00 Talc Merck KGaA/Rona ® Talc 49.50 Potato starchSudstarke GmbH Solanum Tuberosum 7.50 (Potato Starch) Magnesium stearateMerck KGaA/Rona ® Magnesium Stearate 2.50 Phase B Isopropyl stearateCognis GmbH Isopropyl Stearate 9.14 Cetyl palmitate Merck KGaA/Rona ®Cetyl Palmitate 0.53 Ewalin 1751 H. Erhard Wagner Petrolatum 0.53 GmbHPerfume oil Elegance # Haarmann & Perfume 0.20 79228 D MF Reimer GmbHPropyl 4-hydroxy- Merck KGaA/Rona ® Propylparaben 0.10 benzoate

[0082] Preparation:

[0083] Combine and pre-mix the constituents of phase A. Subsequently addthe molten phase B dropwise to the powder mixture with stirring. Thepowders are pressed at from 40 to 50 bar.

Example G Nail Varnish

[0084] Raw material Source of supply INCI [%] Pigment from Merck KGaA2.00 Example 1 Thixotropic International Toluene, Ethyl Acetate, 98.00nail varnish Lacquers S.A. Butyl Acetate, Nitro- base 1348 cellulose,Tosyl- amide/Formaldehyde Resin, Dibutyl Phthalate, Isopropyl Alcohol,Stearalkonium Hectorite, Camphor, Acrylates Copolymer, Benzophenone-1

[0085] Preparation:

[0086] The pigment is weighed out together with the varnish base, mixedwell by hand using a spatula and subsequently stirred at 1000 rpm for 10minutes.

Example H Lip Lacquer

[0087] Raw material Source of supply INCI [%] Phase A Pigment fromExample 1 Merck KGaA 2.50 Timiron ® Splendid Violet Merck KGaA/Rona ®MICA, Silica, Cl 77891 5.00 (Titanium Dioxide) Xirona ® Indian SummerMerck KGaA/Rona ® Silica, Cl 77491 (Iron 2.50 Oxides) Rubis Covapate W4765 Les Colorants Ricinus Communis 5.00 Wackherr (Castor Oil), Cl 15850(D&C Red No. 7 Calcium Lake) Phase B Foralyn 5020-F Hercules BV MethylHydrogenated 20.00 Rosinate Adeps Lanae Henry Lamotte Lanolin 18.00 GmbHCastor oil Henry Lamotte Ricinus Communis 13.75 GmbH (Castor Oil) Foral85-E Hercules BV Glyceryl Hydrogenated Rosinate 12.00 Jojoba oil GustavHeess Buxus Chinensis 5.00 GmbH (Jojoba oil) Eusolex ® 2292 MerckKGaA/Rona ® Ethylhexyl Methoxy- 3.00 cinnamate, BHT Antaron V-216 ISPGlobal PVP/Hexadecene 4.00 Technologies Copolymer Candelilla Wax 2039 LKahl & Co. Candelilla Cera 3.50 (Candelilla Wax) Amerchol L 101 AmercholLanolin Alcohol, 3.00 Paraffinum Liquidum (Mineral Oil) Rohagit S RohmGmbH Acrylates Copolymer 1.50 Beeswax white Merck KGaA/Rona ® Cera Alba(Beeswax) 1.00 Propyl 4-hydroxy- Merck KGaA/Rona ® Propylparaben 0.10benzoate Oxynex ® K liquid Merck KGaA/Rona ® PEG-8, Tocopherol, 0.05Ascorbyl Palmitate, Ascorbic Acid, Citric Acid Phase C FragranceTendresse # Haarmann & Perfume 0.10 75418C Reimer GmbH

[0088] Preparation:

[0089] Warm all constituents (apart from the Foral 85-E) of phase B to80° C. and slowly add the Foral 85-E with stirring. Add phase A andphase C to the molten phase B. Pour the homogeneous melt into the mouldat 50° C.

[0090] The entire disclosure[s] of all applications, patents andpublications, cited herein and of corresponding German application No.103 13 978.8, filed Mar. 27, 2003 and is incorporated by referenceherein.

[0091] The preceding examples can be repeated with similar success bysubstituting the generically or specifically described reactants and/oroperating conditions of this invention for those used in the precedingexamples.

[0092] From the foregoing description, one skilled in the art can easilyascertain the essential characteristics of this invention and, withoutdeparting from the spirit and scope thereof, can make various changesand modifications of the invention to adapt it to various usages andconditions.

[0093] Upon further study of the specification and appended claims,further objects and advantages of this invention will become apparent tothose skilled in the art.

1. A pigment, comprising a transparent, platelet-shaped substrate,having a refractive index ≦1.9, and an average thickness of individualplatelets within a standard deviation of ≦20%, and on said substrate acoating of TiO₂ and optionally an outer protective layer, said pigmenthaving a silver interference color.
 2. A silver pigment according toclaim 1, wherein the TiO₂ coating has a layer thickness of 5-300 nm. 3.A silver pigment according to claim 1, wherein the substrate is an SiO₂platelet, Al₂O₃ platelet, a polymer platelet, a single crystal or aglass platelet.
 4. A silver pigment according to claim 2, wherein thetransparent platelet is an SiO₂ platelet.
 5. A silver pigment accordingto claim 1, wherein the average thickness of individual platelets iswithin a standard deviation of ≦10%.
 6. A silver pigment according claim1, wherein the TiO₂ is in the rutile modification.
 7. A process for thepreparation of a silver pigment according claim 1, comprising a coatingof the substrate by wet-chemical methods, by hydrolytic decomposition ofmetal salts in aqueous medium or by thermal decomposition by a CVD orPVD process.
 8. A process according to claim 7, wherein the TiO₂ coatingis matched to the substrate as to produce a silver interference color.9. In a paint, coating, printing ink, security printing ink, plastic,button paste, ceramic material, glass, seed coating, dopant for lasermarking of plastics or papers, an additive for coloring of foods orpharmaceuticals or, cosmetic formulation comprising a pigment theimprovement wherein the pigment is one according to claim
 1. 10. Apigment composition comprising at least one binder, at least one silverpigment according to claim 1, and optionally conventional additives. 11.A dry preparation comprising pellets, granules, chips or briquettes of asilver pigment according to claim
 1. 12. A silver pigment, comprising atransparent, platelet-shaped substrate, having a refractive index ≦1.9,and an average thickness of individual platelets within a standarddeviation of ≦20%, and on said substrate a coating of TiO₂ having alayer thickness of 5-300 nm and optionally an outer protective layer.13. A silver pigment, consisting of a transparent, platelet-shapedsubstrate, having a refractive index ≦1.9, and an average thickness ofindividual platelets within a standard deviation of ≦20%, and on saidsubstrate a coating of TiO₂ having a layer thickness of 5-300 nm andoptionally an outer protective layer.
 14. A silver pigment, comprising atransparent, platelet-shaped substrate, having a refractive index ≦1.9,and an average thickness of individual platelets within a standarddeviation of ≦20%, and on said substrate a coating consisting of TiO₂having a layer thickness of 5-300 nm and optionally an outer protectivelayer.